In many circuits, a need for a fixed or determined voltage for internal or external purposes exists. Such a fixed or determined reference voltage may, for instance, be generated by a bandgap circuit based on an externally or internally provided supply voltage.
The presence of such a reference voltage may, for instance, represent a prerequisite for an operation of further circuits or parts of such a circuit. Hence, a controlled power-up reducing the probability of an improper initiation of the circuit providing such a reference voltage may be desirable for the operation of the whole circuit.